CHRIS HAMMER: Andrew Leigh, given that it appears that it's unlikely there will be a vote in Parliament on same-sex marriage and there's now a debate about plebiscites verses referendums before, during or after the election, where do you think we should head?

ANDREW LEIGH, SHADOW ASSISTANT TREASURER: Chris, I think people are making this more complicated than it needs to be. When the Marriage Act was changed in 2004 to prevent same-sex marriage, none of the conservatives – Tony Abbott included – said that that should go to the people. The talk now of a plebiscite or referendum is just a delaying tactic, a blocking tactic which is, as today's polls show, against the wishes of two-thirds of Australians.

HAMMER: It's not a scuttling tactic?

LEIGH: It's probably that as well. But this is not a reform which ought to be threatening to Australians. This will strengthen traditional marriages, not weaken them. It will put us in the position of following the rest of the advanced countries in the English speaking world – countries like New Zealand, Britain, Ireland and the United States where the forecast plagues of locusts have not materialised since same-sex marriage has been allowed.

HAMMER: How do you counter that line from the Government: let the people decide not the politicians?

LEIGH: That's certainly not the Government's argument when it comes to their broken promises; when it comes to cuts to the pension, health, education and the ABC. It wasn't their argument when they changed the Marriage Act in 2004. Same-sex marriage is, as Tony Abbott said after the Irish referendum, a matter for the Australian Parliament.

HAMMER: OK, let's move on to tax reform. A Senate Committee has been examining multinational tax, their report is expected to be released today. It's thought to recommend a number of reforms including naming and shaming multinationals without paying their tax, revealing the tax settlements that are, at the moment, private if companies settle out in court. What do you make of these sorts of reforms?

LEIGH: The Senate committee has done good work and I'll be interested to read their report when it comes out. I do think that in this area, the Coalition is a lot of hot air but very little action. Joe Hockey this morning was claiming credit for tax transparency laws which he is right now, in the Parliament, trying to wind back. When they were in Opposition, the Coalition voted against Labor's major multinational tax package. When they came to office they gave back a billion dollars worth of tax breaks to large multinationals. The Coalition’s latest multinational tax plan is so woolly that Treasury can't cost it. That stands in clear contrast to Labor's package which is costed by the Parliamentary Budget Office, informed by work from the OECD, which raises over $7 billion in the next decade.

HAMMER: What do you think though of this proposal of naming and shaming large companies?

LEIGH: We'll certainly look carefully at any recommendations that come out of the Senate inquiry. But the key battleground for transparency right now is between Labor, which believes that firms with a turnover in excess of $100 million ought to have their total income, taxable income and tax paid reported; and the Coalition which has taken the stance of secrecy. This is despite the fact that they responded to a Freedom of Information request by saying that they received no correspondence calling on them to take that stance.

HAMMER: What effect though would transparency have on these big international companies? Are they going to care what the Australian public think?

LEIGH: It certainly has had an impact in other contexts. There’s been strong impact from publicity around the PricewaterhouseCoopers ‘Lux Leaks’ case, the publicity about Starbucks in Britain not paying its fair share, around firms such as Google and Apple which take very seriously their customer relations. Justice Louis Brandeis in the US once said that ‘sunlight is the best disinfectant’, and I think that providing more information about the tax affairs of big companies allows us to have a well informed debate. I find it very strange when people on one hand criticise reports like that from the Tax Justice Network saying they're based on imperfect information, but then the other, oppose the release of accurate information so we can have sensible discussion.

HAMMER: The Attorney General, George Brandis, has suggested reform in the Environmental Protection Act and he says it's open to abuse with so-called vigilante litigation. What do you think about that just as a general principle – that big, economically important developments can be held up in the courts on technicalities?

LEIGH: This Government has never seen an environmental group that it doesn't want to defund or shut down. It is trying at the moment, through a House inquiry, to remove the tax deductible recipient status for environmental charities. It claims that there is nefarious activity in environmental charities but has produced very little evidence of it. Frankly, if there are concerns about environmental NGOs doing the wrong thing, that can be handled through Australia’s charities commission, which the Abbott Government is committed to abolishing. We need to make sure that we have a strong civil society in Australia. I don't always agree with the things that green groups say or that environmental NGOs say, but I do respect their role in a sensible public debate.

HAMMER: But do you think the act needs to be reformed?

LEIGH: I don't. I believe that we've got the balance right at the moment and that environmental groups – both when they're right and when they're wrong – play an important role in a mature democracy.